The present invention relates to a propeller shaft for marine drive units, comprising a first portion with alternating external axial keyways and keys designed for fitted engagement with internal keys and keyways on a hub portion of a propeller and, between one end shaft and said first portion, a second portion with external threads for engagement with an element provided with internal threads.
The invention also relates to a propeller for marine drive units, comprising a hub portion with alternating internal keyways and keys intended to engage corresponding external keys and keyways on a propeller shaft portion.